2
Draw two cross sections on the other side of this page, one across the region of modern Italy, the other across western U.S. at ~370 Ma (during the Antler orogeny). List some of the major similarities and differences. On the western U.S. cross section, show the topographic divide. The following passage is in Burchfiel and Royden: Explain briefly why each of these is important, and include these ideas in your cross section. Following Burchfiel nd Royden, sketch the position of the Klamath-Sierran volcanic arc, Havallah Basin, Antler allocthon and Antler foredeep at an initial stage of development, and at a late stage of development. Show where extension is occurring, sediment transport (arrows going from source to sink), and the topographic divide. (Basin and Range extension has widened the area between the hingeline and the rift margin. Draw your sketch on the map shown, which is of the current locations.) Antler Orogeny (again) hinge- line
